Kunzea ambigua is a spreading shrub that reaches 4 metres by 4 metres wide.
It is a very common species with a large natural and mainly coastal geographic range. In NSW, it grows as far south as the Victorian border in coastal areas, extending north almost continuously to Newcastle. There are then sporadic occurrences from Port Stephens to the Queensland border, again along the coast. There are a few inland records on the Northern Tablelands and inland North Coast. In Victoria, it is natural to the far north-east corner and reported to be natural as far east as Wilsons Promontory. Occurrences further west are said to be weedy, naturalising from cultivation. It occurs naturally through most of eastern Tasmania and the islands of Bass Strait. It extends into Queensland along the coast, as far as Tewantin.
It typically grows in dry to moist sclerophyll woodland and forest, as well as open regenerating shrublands (where it can be the dominant shrub) and heathland, usually on sandstone to sandy soils but also shale-sandstone transition and alluvium. This species can form its own monoculture in some cleared patches which are allowed to regenerate and can be prolific after fire. It also grows in disturbed areas such as edges of landfill-bushland and paddock-bushland interfaces.
Kunzea spp. have simple and alternate or opposite to clustered leaves, often aromatic. In this species, they are alternate but heavily clustered, to 12 mm long and 1.5 mm wide with an acute point and sometimes with hairs. They are aromatic and mid to dark green.
Kunzea spp. have conspicuously staminate flowers, like many of their myrtle-relatives, with 5 sepals petals, in a range of colours, white, red, purple, pink or yellow (depending on species). Each flower has numerous stamens surrounding one carpel. Flowers are usually produced in high numbers in terminal or sub-terminal clusters or heads; rarely as solitary flowers or in clusters of 2s or 3s. In this species, flowers are produced in sub-terminal leaf axils creating leafy side branches; white in colour, which each flower about 20 mm across if the spreading stamens are included. The stamens of each flower meld into each other, creating a bounteous flowering effect, produced mainly in October to November and smelling strongly of honey. The flowers attract a wide range of native insects including bees, beetles and wasps.
The fruit of Kunzea is a capsule. In this species, it is about 3 mm long and 4 mm wide, which will release many small seeds.
This plant can be easily cultivated and has been grown for a long time. They are typically easy to establish and are tolerant of many soils. Heavy clay may reduce its vigour but any soils with reasonable drainage should work well.
It needs some room to spread out and it can get leggy. Regular pruning of plants should keep it nice. A favourite for insects when it is flowering.
It may fall victim to webbing caterpillars which can always be removed using a gloved-hand.
Plants respond positively to pruning after flowering.
In our cold climate garden, we find seedlings appearing regularly.
There is also a pink flowered form. We also have a semi-prostrate form that develops into a mounded ground cover.
Kunzeas are trouble free and are a most desirable genus of attractive plants to grow in any garden. The floral beauty of infinite variation attracts beneficial insects and nectar loving birds
Slow release native plant fertiliser can be advantageous to growth and health of plants.
Kunzea spp. can generally be progated by seed or cuttings.
If grown from seed, flowering may take 6 years. However, cuttings taken from semi-hardwood tip cuttings, taken in late spring through to early autumn could produce flowers in one year or two at the latest.
One tip I always give for this species is to drive up the M1 Freeway in NSW, between Gosford and Newcastle in October to November and put the window down and enjoy the heady honey-odour. It comes from this species, when flowering, growing extensively on the freeway median strip and adjoining bushland.
Kunzea is a genus of about 60 species, found in Australia and New Zealand. Australia has about 50 species – all endemic. Some species are used for essential oil. NSW currently has 15 species.
Kunzea spp. will generally profusely sucker from root zones after fire, as well as regenerate from seed.
Kunzea – named after Gustav Kunze (1793-1851) – a German professor of zoology and an entomologist and botanist. Kunze was eventual Director of the Botanic Gardens of Leipzig. The genus was named after him by botanist Ludwig Reichenbach.
ambigua – Latin meaning ‘uncertain’ or ‘doubtful’ – possibly referring to its first name, Leptospermum ambiguum, where the author was doubtful that this species was indeed a Leptospermum.
This species is not considered to be at risk of extinction in the wild.
NSW Flora Online (PlantNET) – Kunzea ambigua profile page https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Kunzea~ambigua
Gardening with Angus – Kunzea ambigua profile page https://www.gardeningwithangus.com.au/kunzea-ambigua-tick-bush/
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.
Australian National Herbarium – Kunzea ambigua profile page https://www.anbg.gov.au/gnp/gnp8/kunz-amb.html